Mega Manila is a megalopolis on the island of Luzon, Philippines. There are varying definitions of the megalopolis, but it is generally seen as encompassing the administrative regions of Central Luzon, Calabarzon, and Metro Manila. On some occasions, the administrative region of Mimaropa is also included. It is frequently used in the press, advertising, television, and radio to refer to provinces bound to Manila, in contrast to the term Greater Manila Area, which is academically used to describe the urbanization process that has long spilled out of Metro Manila's borders, also known as the built-up area. Mapping out the built-up area around Manila requires finer granularity than the more generic term Mega Manila. Mega Manila is used in general reference to the relationship of Metro Manila to surrounding provinces. It references only provinces and not the exact settlement patterns of cities, towns, and barangays, which may be urban, suburban, mountains, or rural areas that are still part of provinces close enough to Manila to be lumped into the definition. Definitions Philippine Information Agency Mega Manila, as a loose metropolitan area defined by the Philippine Information Agency (PIA), is divided into the National Capital Region (Metro Manila) and the suburbs of Central Luzon, Calabarzon, and Mimaropa. Mega Manila's 2015 population was projected at 40,368,979 or 40% of the country's population, and covers roughly half of Luzon, with an area of 52,097.66 square kilometers, including many rural areas. National Economic and Development Authority The National Economic and Development Authority (NEDA) defines Mega Manila as Metro Manila and the surrounding specific provinces of Bulacan, Rizal, Cavite, and Laguna, especially on its study "Roadmap for Transport Infrastructure Development for Metro Manila and its Surrounding Areas (Region III and Region IV-A)". Notably, these collection of areas is also known as the Greater Manila Area. Meanwhile, the NEDA study, which is a collaboration with the Japan International Cooperation Agency (JICA), considers Metro Manila, Central Luzon, and Calabarzon as the Greater Capital Region (GCR). TV rating companies TV ratings agency AGB Nielsen Philippines and Kantar Media Philippines consider Metro Manila and the provinces of Bulacan, Cavite, Laguna and Rizal as "Mega Manila" for their TV ratings gathering (area highlighted in blue on the map), a much stricter definition than the PIA. Using census population in 2010 the area has a population of 25,066,000 or about 26.6% of the population in an area roughly the size of Los